Understanding Sliding Filament Theory

What is the primary function of the sliding filament theory in muscle contraction?

• To explain the role of calcium in muscle relaxation

• To describe how muscles generate force and shorten

• To illustrate the process of muscle fatigue

• To detail the synthesis of ATP in muscle cells

Which two proteins are primarily involved in the sliding filament mechanism?

• Troponin and tropomyosin

• Myosin and actin

• Collagen and elastin

• Keratin and fibrin

How does calcium influence muscle contraction?

• It binds to myosin, allowing it to attach to actin

• It binds to troponin, causing a conformational change that exposes binding sites on actin

• It provides energy for the contraction process

• It breaks down ATP to release energy

What is the role of ATP in muscle contraction?

• It provides the energy needed for myosin to detach from actin

• It binds to actin, allowing myosin to attach

• It stabilises the muscle fibres during contraction

• It acts as a neurotransmitter in muscle cells

Which stage of the sliding filament model involves the power stroke?

• Attachment of myosin to actin

• Release of calcium ions

• The pulling of actin filaments by myosin heads

• Detachment of myosin from actin

What happens to the sarcomere during muscle contraction according to the sliding filament theory?

• It lengthens

• It shortens

• It remains the same length

• It disintegrates

Which of the following best describes the role of myosin heads during muscle contraction?

• They bind to calcium ions

• They form cross-bridges with actin filaments

• They synthesise ATP

• They release neurotransmitters

What is the initial trigger for the release of calcium ions in muscle cells?

• The breakdown of ATP

• An action potential reaching the muscle fibre

• The binding of myosin to actin

• The relaxation of the muscle